Slow-moving or stationary vehicles on a roadway are at risk of being struck from behind when traffic conditions are such that other vehicles traveling in the same direction are moving at faster speeds. Drivers approaching a slow-moving or stationary vehicle might not expect to need to brake quickly, might misjudge speed differences, or might not notice the vehicle ahead. One common scenario is a night-time, left hand turn from a busy thoroughfare to a residential street where no traffic light is present. The left hand turn may be delayed by oncoming traffic and the vehicle may be stationary while waiting to turn. The stationary vehicle can be at risk of being struck by fast moving vehicles approaching from behind.
Experienced drivers might attempt to alert other drivers approaching from behind that the vehicle the driver is piloting has stopped or has reduced speed with a visual indication using brake lights located at the tail of the vehicle in front. One common practice for vigilant drivers is to “pump” or rapidly release and depress the brake pedal to toggle the tail brake lights and therefore make them more conspicuous to alert the driver of the oncoming vehicle to take action. However, in the left hand turn scenario, the driver of the stationary vehicle in front might not be aware of vehicles approaching from behind. Often drivers making a left hand turn are focused on the oncoming traffic in order to safely complete the turn.
It would be desirable to implement a rear collision alert system.